The objectives and specific aims of the proposal are to examine the usefulness of experimental epilepsy produced in the rat by cerebral implantation of cobalt as an alternative screening method for the evaluation of potential anticonvulsants. Cobalt-epileptic rats will be prepared with permanent electrodes for continuous monitoring of electrocorticographic (ECOG) and electromyographic (EMG) activity, and with indwelling polyethylene cannulas for drug administration. The effects of drugs on seizure incidence and on duration of polyspikes will be determined. Drugs to be tested include: (1) three new clinically available anti-epileptic drugs, valproate, clonazepam and carbamazepine; (2) compounds which have been shown to be effective anticonvulsants in preliminary screening, but which are not presently available clinically.